geomorphology Geomorphology () is the scientific study of the origin and evolution of topographic and bathymetric features generated by physical, chemical or biological processes operating at or near Earth's surface. Geomorphologists seek to understand wh ...

, a stream head cut or simply head cut (alternately headcut) is an erosional feature of some intermittent and

perennial In horticulture, the term perennial ('' per-'' + '' -ennial'', "through the year") is used to differentiate a plant from shorter-lived annuals and biennials. It has thus been defined as a plant that lives more than 2 years. The term is also ...

stream A stream is a continuous body of water, body of surface water Current (stream), flowing within the stream bed, bed and bank (geography), banks of a channel (geography), channel. Depending on its location or certain characteristics, a strea ...

s. Headcuts and

headward erosion Headward erosion is erosion at the origin of a stream channel, which causes the origin to move back away from the direction of the stream flow, lengthening the stream channel.Essentials of Geology, 3rd Ed, Stephen Marshak It can also refer t ...

are hallmarks of unstable expanding drainage features such as actively eroding gullies. Headcuts are a type of

knickpoint In geomorphology, a knickpoint or nickpoint is part of a river or channel where there is a sharp change in channel bed slope, such as a waterfall or lake. Knickpoints reflect different conditions and processes on the river, often caused by pre ...

that, as the name indicates, occur at the head (upstream extent) of a channel. The knickpoint, where a head cut begins, can be as small as an overly-steep

riffle A riffle is a shallow landform in a flowing channel. Colloquially, it is a shallow place in a river where water flows quickly past rocks. However, in geology a riffle has specific characteristics. Topographic, sedimentary and hydraulic indica ...

zone or as a large as a

waterfall A waterfall is any point in a river or stream where water flows over a vertical drop or a series of steep drops. Waterfalls also occur where meltwater drops over the edge of a tabular iceberg or ice shelf. Waterfalls can be formed in seve ...

. When it is not flowing, the head cut will resemble a very short

cliff In geography and geology, a cliff or rock face is an area of Rock (geology), rock which has a general angle defined by the vertical, or nearly vertical. Cliffs are formed by the processes of weathering and erosion, with the effect of gravity. ...

bluff Bluff or The Bluff may refer to: Places Australia * Bluff, Queensland, Australia, a town * The Bluff, Queensland (Ipswich), a rural locality in the city of Ipswich * The Bluff, Queensland (Toowoomba Region), a rural locality * Bluff River (New ...

. A small

plunge pool A plunge pool (or plunge basin or waterfall lake) is a deep depression in a stream bed at the base of a waterfall or Shut-in (river), shut-in. It is created by the erosion, erosional forces of cascading water on the rocks at the formation's bas ...

may be present at the base of the head cut due to the high energy of falling water. As erosion of the knickpoint and the streambed continues, the head cut will migrate upstream. Groundwater

seeps A petroleum seep is a place where natural liquid or gaseous hydrocarbons escape to the Earth's atmosphere and surface, normally under low pressure or flow. Seeps generally occur above either natural terrestrial or underwater petroleum accumul ...

and springs are sometimes found along the face, sides, or base of a head cut.North Carolina Division of Water Quality, "Identification Methods for the Origins of Intermittent and Perennial Streams, Version 3.1", February 28, 2005

Channel Channel, channels, channeling, etc., may refer to: Geography * Channel (geography), a landform consisting of the outline (banks) of the path of a narrow body of water. Australia * Channel Country, region of outback Australia in Queensland and pa ...

incision is very common when head cuts are involved in stream morphology. In terms of stream restoration, head cuts are one of the most difficult challenges. Installing

check dam A steel check dam A check dam is a small, sometimes temporary, dam constructed across a swale, drainage ditch, or waterway to counteract erosion by reducing water flow velocity. Check dams themselves are not a type of new technology; rather, t ...

s or elevating the stream by filling the gully are common ways to mitigate up stream migration of the knickpoint. Another common way to control the knickpoint is by sloping the bank face by laying down fabric and rock.

References

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External links

* North Carolina Division of Water Qualit

Stream restoration problems
Geomorphology Fluvial landforms Erosion landforms